(a) Field of the Invention
This invention relates to a method for preventing articulation of chain joints in one direction in a suspended, endless, chain assembly. The method for limiting chain joint movement is provided by an addition of a chain link extension, such as a chain plate and the like attached to one end of a pair of parallel sidebars. The sidebars, with barrel and connecting pin, are used in making up the endless chain assembly. The method of limiting the joint articulation in a chain assembly is a critical element in a design of certain machinery used in the fields of waste water treatment, water treatment, and other mechanisms. This is particularly true with a chain assembly driven by a drive sprocket and without the use of an idle sprocket.
(b) Discussion of Prior Art
A method of limiting chain joint articulation in one direction, particularly inwardly on a suspended chain assembly, can provide a means of simplifying a design of certain machines and thereby increase reliability, economy, and reduce maintenance.
In the U.S., where most of modern chain design has occurred, U.S. Pat. Nos. 2,226,989 and 2,235,854 teach the design of a chain and chain attachments that freely articulate in one direction (away from the attachment side), but restrict the amount of articulation toward the attachment side. This type of articulation limiting is achieved by abutting surfaces within a chain joint. In U.S. Pat. No. 5,425,875, a chain design incorporates this concept with limited articulation in one direction, which is linear, by simply rotating the abutting surfaces in the chain joint.
Other methods of limiting articulation include extending a portion of the chain link side-bar into the interior of the adjacent chain link where an extension contacts an integral boss in the link. This feature limits articulation to linear and is shown as a Link-Belt cast manganese steel Apron Feeder chain, 1952. Another method is that used by Caterpillar Tractor and others whereby abutting ends of the forged steel crawler links abut each other, with further back bend limited also by abutting grouser (shoe) plates.
None of these prior art articulation limiting designs provide a method for limiting chain joint articulation in one direction using a chain link extension and the like as disclosed herein.